Relaxation induced by red wine polyphenolic compounds in rat pulmonary arteries: lack of inhibition by NO-synthase inhibitor.

Some red wine polyphenols exert nitric oxide (NO)-dependent relaxation in systemic arteries, following activation of endothelial NO synthase (eNOS). In this study, the effect of red wine polyphenols was determined in rat intrapulmonary arteries, and the effect of some of these compounds was compared with the responses obtained in rat aorta. In pulmonary arteries, red wine polyphenolic extract (> 300 microg/mL) exerted relaxation that was not inhibited by the NOS inhibitor N(omega)-nitro-L-arginine methylester (L-NAME) or endothelium removal.